Transcript for Motorcyclist records hit-and-run, then follows driver
They go inside a motorcycle chase. He is making his night line debut. The dramatic California highway chase with the dangerous twist. The black Mercedes slammed into the back of two other vehicles near San Bernardino. Whoa! The crash and what happens next all caught on a motorcyclist go pro. The rider jumping off when the driver of that badly damaged Mercedes took off. Hey! The witness turned gd samaritan making a split second decision to chase after the driver, calling 911. I'm in pursuit of a hit-and-run driver. The chase hitting the freeway. He is swerving back and forth. Downside streets and the parking lot. Back on again. The bumper just fell out and hit me. The highway drama lasting for nearly 20 miles before highway patrol finally catches up. Troopers arresting 62-year-old Nathaniel Sylvester and saying he felt he had no choice. I didn't top the get involved. As soon as he took off before hitting multiple cars. I knew I had to chase them down before they kill anybody else. The troopers offer advice in return. Don't chase suspects, but we are grateful for the help. For night line in Los Angeles. It was booker T Washington who said those who are happy and those who do the most for others.
This transcript has been automatically generated and may not be 100% accurate.